The potential for TVs to eavesdrop is revealed in Samsung's smart TV privacy policy available on its website.

"Please be aware that if your spoken works include personal or other sensitive information, that information will be among the data captured and transmitted to a third party through your use of Voice Recognition," the policy said.

For the voice command feature to work, third party software translates speech into text and sends the command back to the TV.

Users can give commands to the TV's built-in microphone such as "find me an action movie," which causes the TV to search as instructed. As the TV collects voice commands, it also transmits other information as its individual ID.

Samsung said data collection is aimed at improving TV performance but users can disable it.

It is not the first time that smart TVs sparked privacy concerns. In 2013, a user revealed that LG Electronics smart TV was sending information about his viewing habits back to the company without consent and without encrypting data.

LG has also experimented with displaying targeted ads on its smart TVs, which requires collecting and utilizing user data, such as their location, age and gender.